We thank Mr Lee Seong Wee for his letter (Tackle flaws in testing, certifying cladding; Dec 19).

The Singapore Civil Defence Force's (SCDF) requirement to perform tests on the core of aluminium composite panels (ACPs) has been in place since 2008. Testing on the core is practised in several other countries.

Accredited laboratories prepare the test samples by removing the non-combustible aluminium skin on the panel to expose the core. After doing so, the condition of the core could be uneven and may have remnants of adhesive which was used to bond the layers of the panel together. However, these do not alter the result of the test in any significant way.

The practice of using Certificates of Conformity (COCs) issued by certification bodies to verify that ACPs meet fire safety requirements is a common practice in many countries.

In Singapore, certification bodies are subject to accreditation and checks, and are required to conduct annual audits to ensure that ACP models continue to comply with their COCs.

If an ACP model fails the audit, its COC will be suspended or terminated.

Investigations are ongoing as to how models of ACPs which do not meet the standard specified on their COCs came to be installed on some buildings in Singapore.

The SCDF is also reviewing the fire safety regulations and certification requirements on the use of ACPs as cladding.

Leslie Williams (Lieutenant-Colonel)

Senior Assistant Director (Public Affairs Department)

Singapore Civil Defence Force